arXiv
(422,153 recursos)
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Mostrando recursos 81 - 100 de 9,277
81.
Relational Algebra as non-Distributive Lattice - Tropashko, Vadim
We reduce the set of classic relational algebra operators to two binary
operations: natural join and generalized union. We further demonstrate that
this set of operators is relationally complete and honors lattice axioms.
82.
Consistency Problems for Jump-Diffusion Models - Bayraktar, Erhan; Chen, Li; Poor, H. Vincent
In this paper consistency problems for multi-factor jump-diffusion models,
where the jump parts follow multivariate point processes are examined. First
the gap between jump-diffusion models and generalized Heath-Jarrow-Morton (HJM)
models is bridged. By applying the drift condition for a generalized
arbitrage-free HJM model, the consistency condition for jump-diffusion models
is derived. Then we consider a case in which the forward rate curve has a
separable structure, and obtain a specific version of the general consistency
condition. In particular, a necessary and sufficient condition for a
jump-diffusion model to be affine is provided. Finally the Nelson-Siegel type
of forward curve structures is discussed. It is demonstrated that under
regularity condition, there...
83.
On The Tradeoff Between Two Types of Processing Gain - Fishler, Eran; Poor, H. Vincent
One of the features characterizing almost every multiple access (MA)
communication system is the processing gain. Through the use of spreading
sequences, the processing gain of Random CDMA systems (RCDMA), is devoted to
both bandwidth expansion and orthogonalization of the signals transmitted by
different users. Another type of multiple access system is Impulse Radio (IR).
In many aspects, IR systems are similar to time division multiple access (TDMA)
systems, and the processing gain of IR systems represents the ratio between the
actual transmission time and the total time between two consecutive
ransmissions (on-plus-off to on ratio). While CDMA systems, which constantly
excite the channel, rely on spreading sequences to...
84.
Extending Design by Contract for Aspect-Oriented Programming - Lorenz, David H.; Skotiniotis, Therapon
Design by Contract (DbC) and runtime enforcement of program assertions
enables the construction of more robust software. It also enables the
assignment of blame in error reporting. Unfortunately, there is no support for
runtime contract enforcement and blame assignment for Aspect-Oriented
Programming (AOP). Extending DbC to also cover aspects brings forward a
plethora of issues related to the correct order of assertion validation. We
show that there is no generally correct execution sequence of object assertions
and aspect assertions. A further classification of aspects as agnostic,
obedient, or rebellious defines the order of assertion validation that needs to
be followed. We describe the application of this classification in a...
85.
Inferring knowledge from a large semantic network - Dutoit, Dominique; Poibeau, Thierry
In this paper, we present a rich semantic network based on a differential
analysis. We then detail implemented measures that take into account common and
differential features between words. In a last section, we describe some
industrial applications.
86.
Multi-document Biography Summarization - Zhou, Liang; Ticrea, Miruna; Hovy, Eduard
In this paper we describe a biography summarization system using sentence
classification and ideas from information retrieval. Although the individual
techniques are not new, assembling and applying them to generate multi-document
biographies is new. Our system was evaluated in DUC2004. It is among the top
performers in task 5-short summaries focused by person questions.
87.
Orchestrating Metadata Enhancement Services: Introducing Lenny - Phipps, Jon; Hillmann, Diane I.; Paynter, Gordon
Harvested metadata often suffers from uneven quality to the point that
utility is compromised. Although some aggregators have developed methods for
evaluating and repairing specific metadata problems, it has been unclear how
these methods might be scaled into services that can be used within an
automated production environment. The National Science Digital Library (NSDL),
as part of its work with INFOMINE, has developed a model of ser-vice
interaction that enables loosely-coupled third party services to provide
metadata enhancements to a central repository, with interactions orchestrated
by a centralized software application.
88.
Clever Search: A WordNet Based Wrapper for Internet Search Engines - Kruse, Peter M.; Naujoks, Andre; Roesner, Dietmar; Kunze, Manuela
This paper presents an approach to enhance search engines with information
about word senses available in WordNet. The approach exploits information about
the conceptual relations within the lexical-semantic net. In the wrapper for
search engines presented, WordNet information is used to specify user's request
or to classify the results of a publicly available web search engine, like
google, yahoo, etc.
89.
Information estimations and analysis of structures - Shaydurov, Alexander
In this paper have written the results of the information analysis of
structures. The obtained information estimation (IE) are based on an entropy
measure of C. Shannon. Obtained IE is univalent both for the non-isomorphic and
for the isomorphic graphs, algorithmically, it is asymptotically steady and has
vector character. IE can be used for the solution of the problems ranking of
structures by the preference, the evaluation of the structurization of subject
area, the solution of the problems of structural optimization. Information
estimations and method of the information analysis of structures it can be used
in many fields of knowledge (Electrical Systems and Circuit, Image recognition,
Computer technology, Databases...
90.
Issues in Exploiting GermaNet as a Resource in Real Applications - Kunze, Manuela; Roesner, Dietmar
This paper reports about experiments with GermaNet as a resource within
domain specific document analysis. The main question to be answered is: How is
the coverage of GermaNet in a specific domain? We report about results of a
field test of GermaNet for analyses of autopsy protocols and present a sketch
about the integration of GermaNet inside XDOC. Our remarks will contribute to a
GermaNet user's wish list.
91.
Transforming Business Rules Into Natural Language Text - Kunze, Manuela; Roesner, Dietmar
The aim of the project presented in this paper is to design a system for an
NLG architecture, which supports the documentation process of eBusiness models.
A major task is to enrich the formal description of an eBusiness model with
additional information needed in an NLG task.
92.
Corpus based Enrichment of GermaNet Verb Frames - Kunze, Manuela; Roesner, Dietmar
Lexical semantic resources, like WordNet, are often used in real applications
of natural language document processing. For example, we integrated GermaNet in
our document suite XDOC of processing of German forensic autopsy protocols. In
addition to the hypernymy and synonymy relation, we want to adapt GermaNet's
verb frames for our analysis. In this paper we outline an approach for the
domain related enrichment of GermaNet verb frames by corpus based syntactic and
co-occurred data analyses of real documents.
93.
Context Related Derivation of Word Senses - Kunze, Manuela; Roesner, Dietmar
Real applications of natural language document processing are very often
confronted with domain specific lexical gaps during the analysis of documents
of a new domain. This paper describes an approach for the derivation of domain
specific concepts for the extension of an existing ontology. As resources we
need an initial ontology and a partially processed corpus of a domain. We
exploit the specific characteristic of the sublanguage in the corpus. Our
approach is based on syntactical structures (noun phrases) and compound
analyses to extract information required for the extension of GermaNet's
lexical resources.
94.
Transforming and Enriching Documents for the Semantic Web - Roesner, Dietmar; Kunze, Manuela; Kroetzsch, Sylke
We suggest to employ techniques from Natural Language Processing (NLP) and
Knowledge Representation (KR) to transform existing documents into documents
amenable for the Semantic Web. Semantic Web documents have at least part of
their semantics and pragmatics marked up explicitly in both a machine
processable as well as human readable manner. XML and its related standards
(XSLT, RDF, Topic Maps etc.) are the unifying platform for the tools and
methodologies developed for different application scenarios.
95.
Some Extensions of Gallager's Method to General Sources and Channels - Yang, Shengtian; Qiu, Peiliang
The Gallager bound is well known in the area of channel coding. However, most
discussions about it mainly focus on its applications to memoryless channels.
We show in this paper that the bounds obtained by Gallager's method are very
tight even for general sources and channels that are defined in the
information-spectrum theory. Our method is mainly based on the estimations of
error exponents in those bounds, and by these estimations we proved the direct
part of the Slepian-Wolf theorem and channel coding theorem for general sources
and channels.
96.
Directed Threshold Multi – Signature Scheme without SDC - Kumar, Manoj
In this paper, we propose a Directed threshold multisignature scheme without
SDC. This signature scheme is applicable when the message is sensitive to the
signature receiver; and the signatures are generated by the cooperation of a
number of people from a given group of senders. In this scheme, any malicious
set of signers cannot impersonate any other set of signers to forge the
signatures. In case of forgery, it is possible to trace the signing set.
97.
Asymptotic Log-loss of Prequential Maximum Likelihood Codes - Grunwald, Peter; de Rooij, Steven
We analyze the Dawid-Rissanen prequential maximum likelihood codes relative
to one-parameter exponential family models M. If data are i.i.d. according to
an (essentially) arbitrary P, then the redundancy grows at rate c/2 ln n. We
show that c=v1/v2, where v1 is the variance of P, and v2 is the variance of the
distribution m* in M that is closest to P in KL divergence. This shows that
prequential codes behave quite differently from other important universal codes
such as the 2-part MDL, Shtarkov and Bayes codes, for which c=1. This behavior
is undesirable in an MDL model selection setting.
98.
Model-Checking Problems as a Basis for Parameterized Intractability - Flum, Joerg; Grohe, Martin
Most parameterized complexity classes are defined in terms of a parameterized
version of the Boolean satisfiability problem (the so-called weighted
satisfiability problem). For example, Downey and Fellow's W-hierarchy is of
this form. But there are also classes, for example, the A-hierarchy, that are
more naturally characterised in terms of model-checking problems for certain
fragments of first-order logic.
Downey, Fellows, and Regan were the first to establish a connection between
the two formalisms by giving a characterisation of the W-hierarchy in terms of
first-order model-checking problems. We improve their result and then prove a
similar correspondence between weighted satisfiability and model-checking
problems for the A-hierarchy and the W^*-hierarchy. Thus we...
99.
Neural network ensembles: Evaluation of aggregation algorithms - Granitto, P. M.; Verdes, P. F.; Ceccatto, H. A.
Ensembles of artificial neural networks show improved generalization
capabilities that outperform those of single networks. However, for aggregation
to be effective, the individual networks must be as accurate and diverse as
possible. An important problem is, then, how to tune the aggregate members in
order to have an optimal compromise between these two conflicting conditions.
We present here an extensive evaluation of several algorithms for ensemble
construction, including new proposals and comparing them with standard methods
in the literature. We also discuss a potential problem with sequential
aggregation algorithms: the non-frequent but damaging selection through their
heuristics of particularly bad ensemble members. We introduce modified
algorithms that cope with this...
100.
TerraServer SAN-Cluster Architecture and Operations Experience - Barclay, Tom; Gray, Jim
Microsoft TerraServer displays aerial, satellite, and to-pographic images of
the earth in a SQL database available via the Internet. It is one of the most
popular online at-lases, presenting seventeen terabytes of image data from the
United States Geological Survey (USGS). Initially de-ployed in 1998, the system
demonstrated the scalability of PC hardware and software - Windows and SQL
Server - on a single, mainframe-class processor. In September 2000, the
back-end database application was migrated to 4-node active/passive cluster
connected to an 18 terabyte Storage Area Network (SAN). The new configuration
was designed to achieve 99.99% availability for the back-end application. This
paper describes the hardware and software components...
81.
